Pocket surveying instrument.



2 SHEETS-SHEET I Patented Apr. 24, 1917.

R. W. RICHARDS.

POCKET SURVEYING INSTRUMENT.

APPLICATION FILED FEB. 5,1916.

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R. W. RICHARDS.

POCKET SURVEYING INSIRUMENT.

APPLICATION FILED FEB. 5, I9I6.

Panted Apr. 24, 1917.

2 SHEETS-SHEET 2.

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RALPH W. RICHARDS, OF'WATERVILLE, MAINE.

POCKET SURVEYING INSTRUMENT.

Specication of Letters Patent.

Patented Apr. 24, 1917.

Application inea February 5, 15516. serial No. 76,383.

To all whom t may concern.:

Be it known that I, RALPH W". RICHARDS, a citizen of the United States, residing at IVaterville, in the county of Kennebec and State of Maine, have invented certain new and useful Improvements in Pocket Surveying Instruments, of which the following is a specification.

This invention relates to pocket surveying instruments, and particularly to that type known as pocket transits My improvements permit the use of the instrument as an alidade, give increased convenience of use as a marching compass, and increase the field of vision when used as a level. Additional features of value are secured by special relations of the parts and will be pointed out hereinafter.

rThe preferred embodiment of the invention is illustrated in the accompanying drawings, in which Figure: 1 is a plan view of the complete device opened out to show the various connected parts thereof;

Fig. 2 is a view of the bottom of the device, as shown in F ig. 1, except that the forward and rear sights are folded down;

Fig. 3 is a view of the device closed, and in condition for use as a marching compass. In this condition it is available for use in orienting plane tables, etc.;

Fig. 4 is a side elevation showing the device arranged for use as an alidade and for analogous purposes;

Fig. 5 is a similar view to Fig. 4 but showing in full lines the device arranged for use as a transit, and in dotted lines the positions assumed by the parts when arranged for use as a level; and

Fig. 6 is an end view of the instrument closed, as in Fig. 3.

The case of the device is formed of a relatively thick case portion 11 and a relatively thin lid portion 12 both rectangular in general form and hinged together by an offset hinge 13, so thatthe outer faces of the case and lid portions swing into a common plane when the device is opened out. The side edges of the case and lid portions also are alined in this condition, and serve as ruling edges when the device is used as an alidade. To facilitate 'such ruling, grooves 14 are formed, as shown, along the edges of the case and lid members, to offer a sharp iducial edge. Graduations 15 are added, different graduations being placed on the different ruling edges if desired.

The portions 11 and 12 are preferably made of aluminum or aluminum alloy to secure lightness and in this case the outer faces are reinforced with bronze or gunmetal plates 16 and 17, so that the ruling or iducial edges shall be relatively hard and durable. The hinge 13 is preferably of bronze or guirmetal as are all other working parts, such as sights, etc. rThe case and lid portions 11 and 12 of the case are so formed as to interengage by means of lugs 1S and recesses 19 when closed, so as frictionally to retain the instrument in closed condition. This also protects the instrument from injury by shocks to which it is liable when carried in the pocket, and which might otherwise destroy the alinement of its parts.

The case portion 11 carries in a suitable recess or chamber the usual magnetic compass. The needle of this is shown at 20, and the graduated dial ring at 21. The cover glass 22 of the compass chamber is sunk below the top surface of the case portion 11 to allow clearance for the front sight to lie between the case portion 11 and lid portion 12 when these are closed together. Also mounted in the compass chamber is the usual pivoted level 23 which is movable by means of a lever 24 housed in a countersink or recess 25 in the outer face of case portion 11. See patent to Brunton No. 526,021, September 1S, 1894). The level is provided with a vernier indeX 26 coacting with a graduated arc 27.

The graduated ring 21 isadjustable to correct for magnetic deviation but as such adjustment is common and is not involved in the present invention the means for securing the adjustment is not shown in the drawings.

The compass needle 2O is damped by a pivoted lever 28 actuated by the depression of a plunger 29 projecting above the top surface of'case portion 11.v This plunger 29 is depressed by the closing of the lid portion 12 as in the Brunton patent above cited. In order, however, to permit the release of the needle when the lid portion is closed I cause the plunger 29 to abut against a pivoted and resilient plate carried by the lid portion 12 instead of causing it to abut against the lid portion itself. This plate 3() is mounted over a recess 31 into which it may be depressed by pressure with the thumbnail to release the needle temporarily. When a continued release is desired the plate 30 is swung out on its pivot 32 to release the plunger 29. A bevel 33 allows it to wipe down plunger 29 when it is swung back.

The front sightconsists of a slotted main portion 34 hinged at 35 to the case portion 11 and having a hinged extension The slot in the portion 34 is bisected longitudinally by a sight wire 37 and the extension is provided with a peep sight 33 and a sighting point 39 as shown. The front sight folds down on hinge 35 across the cover glass 22 and lies in recesses 40 and 41 in case portion 11. The recess 41also accommodates the levels 42 for leveling plane tables, etc., as will be obvious. A luminous point 43 is provided to coact with a luminous tip 44 on needle 20, for convenience of use in night marching.

The lid portion 12 is provided with a sight slot 45 and an aperture 4G which is shown as circular, but may be of any shape desired, for example, rectangular. Countersunk into the inner side of the lid portion 12 is a glass 47 silvered over its entire back, except where it overlies slot 45 and aperture 46. A sight line 48 is engraved in the glass to form a continuation ofthe imaginary center line of slot 45 across the aperture or window 46. l/Vhen the mirror is used the slot 45 serves as a sight'line.

A rear sight 49 is hinged at 50 to lid portion 12 Aand when out of useis housed in a recessin the outer face of the lid portion. It is provided with a sight slot 51 and a sighting notch 52 as shown.

A threaded socket 53 to receive the attaching screw of a tripod is provided.

rEhe axes of hinges 13, 35 and 50 are all perpendicular to the side ruling edges of the case and lid members 11, and 12, and are all parallel to the plane of the outer :faces of members 11 and 12. The sights 37, 33, 39, 45, 48, 51 and 52 all lie in a plane perpendicular to the bottom or outer face of the member 11 and parallel to the side ruling edges thereof in all positions of the sights. Consequently all lines of sight must lie in this plane regardless of what sights are used.

For use as an alidade the device is arranged as shown in Fig. 4, sights 52 and 39 being used. In some cases where a short ruling edge will suffice the lid portion 12 may be placed substantially vertical and the sights 48, 45 and 37 used.

For use as a transit the familiar Brunton method may be adopted with the device in the full line position of Fig. 5 in which the mirror is used. 1n this case the sights are the. slot 45 and wire 37. Where a support is available, so that the compass need not be read while sighting, other arrangements of the sights may be used and will suggest themselves. It should be noted that in the fullline position of Fig. 5 the offset of hinge 13 causes the window 46 to drop below the line of sight. This permits the use of a laro'e window without encroaching on the useful area of the mirror.

For use as a level the device is positioned as shown in dotted lines in Fig. This brings the large window 46 into :the line of sight. The device is held on edge and the oye is placed at the peep sight 38. Sights are taken on the line 48. The bubble is observed in the mirror. The large window is here of the greatest utility permitting the observer to recognize distant objects with certainty.

Use as a marching compass and also for leveling and orienting tables is possible even when the device is closed. As indicated in Fig. 3 the tip 44 of the needle, the north point 43 and the levels 42 are visible through window 4G. All that is necessary is to release the needle by proper actuation of the catch plate 30.

The offset hinge and the special relation existing betwen this and the window are important. The hinge permits the use of a thick casing with a thin lid, where alinement of their edges is necessary when the lid is opened back. r1`he offset hinge with the window set close to the hinge causes the window to drop below the line of sight when the device is used as a reflecting transit. It thus becomes possible to use a much larger window than can be had in prior structures, a feature of great value in all uses of the instrument in which the line of sight is through the window. Examples of such use are when the instrument is used as a level, and as a direct view transit.

lilaving thus described my invention, what i Claim rs1* 1. A pocket surveying instrument coinprising in combination, a casing having a straight ruling edge; al magnetic compass inclosed by said casing; a lid )having a straight ruling edge, a reflecting inner surface, and a sight line on said surface; a hinge connecting said casing and lid for causing their ruling edges to be in alinement to produce a continuous ruling edge when the lid is swung back; and folding sights one carried by the. lid and another by the casing.

2. A pocket surveying instrument comprising in combination a casing having opposed parallel ruling edges; a magnetic compass inclosed by said casing; a lid having opposed parallel ruling edges, a sight slot and a reflecting inner surface; a hinge connecting said casing and lid for causing their ruling edges to be in alinement to produce continuous parallel ruling edges when the lid is swung back; and folding sights one carried by the lid and another bythe casing.

8. A pocket surveying instrument comprising in combination, a casing having a straight ruling edge; a magnetic compass inclosed thereby; a lid provided with a sight slot and a reflecting inner surface; a hinge connecting said casing and lid; and a folding sight carried by said casing.

4. A pocket surveying instrument comprising in combination, a substantially rectangular easing having a side grooved to present a sharp ruling edge; a substantially rectangular lid having a side grooved to present a sharp ruling edge; a hinge connecting said lid and casing and for causing the ruling edges thereof to be in alinement when the lid is opened out; and folding sights one carried by the lid and the other by the casing.

5. In a combined transit and level of the reflecting pocket type, the combination of a casing; a magnetic compass and a leveling device mounted in said casing; a folding sight carried by said casing; a lid for said casing, provided with a reflecting inner surface, a window and a sight line; and a hinge connecting said casing and lid said hinge being offset, for causing the window to be in the line of sight when the lid is adjusted for use of the device as a level, and out of the line of sight when the lid is adjusted for use of the device as a reflecting transit.

6. In a. combined transit and level of the refiecting pocket type, the combination of a casing; a magnetic compass and a leveling device mounted in said casing; a folding sight carried by said casing; a lid for said casing provided with a reflecting inner surface, a window and a sight line; an offset hinge connecting said casing and lid, said hinge and window being so arranged that said window is in the line of sight in the .leveling adjustment of the device, out of tie line of sight in the reflecting transit adjustment of the instrument, and permits a view of the magnetic compass in the closed position of the instrument; means operable by the closing of the lid for damping the needle of the magnetic compass; and means for releasing said damping means while the lid is closed.

7. A combined transit, alidade and level of the pocket type comprising in combination a casing having a straight ruling edge; a magnetic compass and a leveling device mounted in said casing; a lid having a straight ruling edge, a window, a reflecting inner surface, and a sight line extending across said reflectingsurface and window; a hinge connecting said lid and'casing said hinge being offset to bring said ruling edges into alinement when the lid is swung back, and said window being located between said reflecting surface and hinge; and folding sights one carried by said casing and another by said lid.

8. rlhe combination with a pocket surveying instrument including a magnetic compass, folding sight and hinged reflecting lid provided with a window permitting a view of the compass in the closed position of said lid, of a damper for the compass needle normally held in damping position by the lid when closed; and means for releasing said damper while the lid is closed.

9. ln a combined transit and level of the reflecting pocket type, the combination of a casing; a magnetic compass and a leveling device mounted in said casing; a folding sight carried by said casing; a lid for said asing provided with a reflecting inner surface, a window and a sight line; an offset hinge connecting said casing and lid, said hinge and window being so arranged that said window is in the line of sight in the leveling adjustment of the device, out of the line of sight in the reflecting transit adjustment of the instrument, and permits a view of the magnetic compass in the closed position of the instrument; and means for damping and releasing the needle of the magnetic compass while said lid is closed.

ln testimony whereof I have signed my name to this specification.

RALPH W. RICHARDS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

